Propeller for flying machines



Feb. 17, 1931 PIAMHANO 1,792,758

PROPELLER FOR FLYING MACHINES Filed Sept. 9, 1929 3 1 72/43 filigiiiigfl.[HUM/M17517) hununuu -.l-

Inventof 0:77 Vf P/AMP/Aw By I.

Patented Feb. 17, 1931 UNITED STATES OCTIVE PIAMPIANO, OF ROCHESTER, NEW YORK PROPELLER FOR FLYING MACHINES Application filed September 9, 1929. Serial No. 391,221.-

The object of this invention is to provide a new and improved form of propeller for flying machine.

Another object is to increase the surface of the propeller that is available for the purpose of catching the-air and thus increase the driving effect of the propeller.

These and other objects of my invention will be illustrated in the drawing, described in the specification and pointed out in the claims at the end thereof.

In the drawing:

Figure 1 is a front elevation of the propeller looking at it from the bottom of Figure 3.

Figure 2 is a rear elevation of the propeller looking at it from the top of Figure 3.

Figure 3 is a top plan view of the pro peller, the right hand side being cut away in section along the line 3m, 3% of Fig. 5.

Figure 4 is a top plan view of the propeller showing a modification thereof.

Figure 5 is a transverse section through the propeller on the line 5m, Sr of Figure 1.

Figure 6 is a perspective view of the propeller partly broken away.

In the drawing like reference numerals indicate like parts.

In the drawing reference numeral 1 indicates the propeller having a hub 2 which is mounted on a shaft 3. On each side of the hub is a pair of blades, the blades on one side being numbered 4 and 6 and the blades on the other side being numbered 5 and 7. These pairs of bladesare joined togetherat their outerend-s as indicated at 8 and 9.

Between each pair of blades a pocket or passageway extends from front to back through which the air can pass. In this way an increased blade surface is presented to the air thereby increasing the driving effect of the propeller. The upper or leading blade of each pair is narrower than the lower or following blade as is shown in section in Fig. 5. As is also shown in Fig. 5, the pocket or passageway that leads between each pair of blades is curved permitting the air to flow through between the narrow blade and the wide blade with good driving effect. The narrow blades have their forward edges beveled as indicated at 11 in Fig. 5 and the forward edges of the wide blades slope toward the passageway and in this way the leading edges of both blades form openings that are somewhat trough shaped and serve better to catch the air and force it through the pocket openings thereby increasing the driving '12, 12 extending diagonally across the outer surface of the narrow blades. These grooves are adapted to further catch the air and hold it in better contact with the blade thereby increasing the driving force of the blade.

I claim:

1. A propeller having a hub and two blades on each side of the hub, said blades being joined together at the inner and outer ends with a passageway between them, the leading blade of each pair being narrow and the following blade being wide and having its leading edge curved forward and upeven with the leading edge of the narrow blade.

2. A propeller having a hub and two blades on each side of the hub, said blades being joined together at the inner and outer ends with a passageway between them, the leading blade of each pair being narrow and the following blade being wide and having its leading edge curved forward and up even with the leading edge of the narrow blade; the forward edge of the narrow blade being beveled and with the sloping forward edge of the wide blade forming converging sides leading to the passageway between the blades.

In testimony whereof I afiix my signature.

OCTIVE PIAMPIANO. 

